Why are you calculating based on number of tanks of fuel used when you can instead calculate the exact number of gallons? Obviously you have some fuel left when

Why are you calculating based on number of tanks of fuel used when you can instead calculate the exact number of gallons? Obviously you have some fuel left when you get home; that doesn't count as part of the cost of travel because you'll then use it in your normal course of affairs. You've ignored the costs (both monetary and opportunity) of renting a vehicle or using public transit while in the destination city as opposed to having your own vehicle there. You've also ignored the potential harm of being confined to a cabin with scores of people who might be carrying airborne pathogens. You haven't considered the emotional cost of being subjected to an invasive search at the airport, or the stress of getting to your gate on-time. To be clear, I am not anti-flying. I just think it's a sad state of affairs when it's more economically rational for a single individual to drive 450 miles each way than it is to fly. Get a more efficient car, add another person or two, require some bags, or plan an extended stay, and anywhere within a 12-to-24-hour driving radius becomes an economically irrational flight.